A tough regulatory environment and weak oil prices prompted TransCanada to cancel its $12.49 billion Energy East Pipeline, dealing a blow to oil sands producers, who are now more dependent than ever on the Keystone XL and Trans Mountain projects to carry their oil to Gulf Coast refiners and the Pacific Coast. However, the pipeline projects face regulatory hurdles, which means that oil sands producers could be forced to ship more crude by rail, potentially leading some to stop business because of the high costs associated with this transportation method.